2.0 Analysis 2.1 General It was reported that the engine noise had stopped and that the main rotor was slowing as the helicopter passed over the log landing area. An examination of the helicopter after the accident identified negligible rotational damage to the engine, drive train components, main-rotor blades, and tail-rotor blades. Subsequently, a more detailed inspection of the wreckage revealed that all component breakage and damage in the flight controls, drive train, and main-rotor gearbox were overload in nature and were attributable to the impact forces of the accident. Based on this information, it was determined that the helicopter had lost power before impact. A detailed examination of the engine and its accessories revealed several anomalies. While these anomalies may explain the need for a pre-flight compressor wash and for the in-flight power check, they would not have caused a complete power loss. The light bulb analysis showed that the low-fuel light and the right boost pump annunciator light might have been illuminated at the time of the crash. The fuel level sensor is in the left forward cell; therefore, the low-fuel light would indicate that the left forward cell was virtually empty. Assuming the right boost pump became inoperative, the fuel from the left forward cell was consumed at a faster rate than the fuel could transfer from the right forward cell to the left forward cell. The fuel in the left forward cell eventually reached an unusable level, and the engine stopped. The fuel gauge indicator retains its last position when power is cut off. The gauge indication after the crash was 500 pounds. Assuming that power was lost at impact, the gauge was indicating 500 pounds of fuel just before the crash. Relying on the principle that the fuel in the forward cells will remain equal because of the cell interconnect line, the system measures the amount of fuel in the right forward cell, and doubles that amount for the fuel quantity indicator. Therefore, at the moment of the crash, there was approximately 250 pounds of fuel in the right cell and virtually none in the left cell. The boost pump light would indicate that the right boost pump was not operating or that there was no useable fuel in the right fuel cell. In light of the following, it is likely that the pump was not operating (failed): the engine stopped in flight; nothing mechanically wrong was found with the engine; there was useable fuel in the right cell; and the boost pump light might have been on. 2.2 Fuel Delivery System The average length of time that the fuel boost pumps on the Bell 214B were found to operate before requiring repair or overhaul is much lower than the design life goal set by the pump manufacturer. Depending on the attitude of the helicopter, failure of a boost pump in one cell could result in a significant amount of fuel remaining in that cell, while the fuel in the cell with the operable boost pump is consumed to exhaustion. This is because the forward fuel cell interconnect is unable to flow fuel from the cell with the inoperable boost pump to the cell with the operable pump as rapidly as the engine can consume fuel from the cell with the operable boost pump. Exhaustion of the fuel in the cell with the operable boost pump will cause the engine to flame out. 2.3 Fuel Indicating System Because the fuel quantity indicating system does not directly measure the amount of fuel in the left forward cell, unless the fuel level in both forward cells is equal, the gauge will indicate an incorrect amount of fuel remaining. For the same reason, the fuel low-level warning system, which does not directly measure the fuel in the right forward cell, can read incorrectly. Either of these indications could lead the pilot to believe that there is more fuel than is actually available and to continue flight operations until fuel exhaustion. 2.4 Emergency Procedures Pilots may not be aware of the significance of a boost pump failure. The Bell 214B flight manual does not list boost pump failure under Emergency Procedures (Section 3); it is listed under Malfunction Procedures (Section 4). Of the three possible categories of seriousness (land immediately, land as soon as possible, and land as soon as practical), boost pump failure is categorized as the least serious (land as soon as practical). Because the flight manual does not refer to the possibility of incorrect fuel quantity indications following a boost pump failure, the accident pilot may not have regarded the boost pump failure as critical. The low cloud base limited the height above the ground that the helicopter was able to fly. Thus, the helicopter may not have been high enough to carry out a successful autorotation. Because no mechanical malfunction was found that would have contributed to an unsuccessful autorotation and because procedures following a power loss in the Bell 214B require timely and correct pilot response, it is possible that the accident pilot's lack of recent training on Bell 214B emergency procedures contributed to the unsuccessful autorotation. 2.5 Safety Management An occurrence can often be traced back to identifiable organizational and management factors. An examination of whether the company's policies, procedures and practices are in concert and accurately reflect a sound safety philosophy is key to understanding the role of such factors in an occurrence. East West Helicopters had policies and procedures in place to ensure operational compliance and safety. However, as shown in this occurrence, deficiencies uncovered by both the TC post-accident audit and the TSB investigation indicated that the workload of the operations manager compromised operational control and led to operational practices being at odds with safety policies. The nature of the deficiencies identified was such that they could have been identified through a more effective company safety management system. 2.6 Survivability Neither front-seat occupant was wearing his available shoulder harness. Because of the severity and high vertical component of the impact forces in this accident, it is unlikely that the use of the shoulder harness would have prevented fatalities. Given that vertical-reference flying necessitates upper-body freedom of movement, dismissal of the shoulder harness is almost inevitable. It is not known if the crew's rejection of the shoulder harness was deliberate or a continuation of a habit they had developed while heli-logging. It is likely that a crew's regular rejection of shoulder harnesses will diminish their awareness of the safety advantages of shoulder harnesses and, at the same time, reinforce a less-than-ideal safety practice. Accident investigations and research conducted by the TSB have consistently shown that the use of the shoulder harness portion of the seat restraint system is effective in reducing or preventing injury during moderate-impact forces. 3.0 Conclusions 3.1 Findings as to Causes and Contributing Factors The helicopter engine lost power in flight (engine flame-out) because of fuel starvation. The usable fuel in the left cell was exhausted. Although there was fuel in the right cell, it was not available at a usable rate because the right boost pump was inoperative and the fuel transfer was slower than engine fuel usage. When the right boost pump is inoperative, the fuel quantity gauge indicates more fuel than is actually on board. The actual amount of usable fuel would be difficult to determine in flight. 3.2 Findings Related to Risk The model of electric fuel boost pumps used on the Bell 214B helicopter has a history of requiring repair or overhaul well before its expected service life. The pilot did not have a current pilot proficiency check and had not received any recurrent training on type, possibly affecting his ability to conduct an effective autorotation. The Bell 214B flight manual does not adequately describe the consequences of a boost pump failure or emphasize its seriousness. 3.3 Other Findings Neither of the front-seat occupants was wearing the available shoulder harness. The helicopter's weight and centre of gravity were calculated to have been within certificated limits. The certification for this helicopter requires the pilot to be seated in the right front seat during flight with passengers. The pilot was flying from the co-pilot (left front) seat. The helicopter had been modified to be flown from the left seat, but a supplemental type certificate had not been issued by Transport Canada. The helicopter was not maintained in accordance with existing regulations and approved procedures: information was not transcribed to the technical logbook within the required 30 days. 4.0 Safety Action 4.1 Action Taken Transport Canada (TC) audited the company on 14 July 1999 and found the flight crew training program was lacking in several areas. TC staff have indicated that the company corrected all the items noted in the audit and that the company has been put on a one-year audit cycle. See Section 1.17.2 of this report. 4.2 Action Required While the findings in this investigation relate to the Bell 214B, some of the findings are valid for the Bell 205, though to a lesser extent because of the reduced fuel flow requirements of the Bell 205. Of the 34 Bell 214Bs operating commercially around the world, 8 are in Canada or under Canadian registration. Of the 200 Bell 205s operating commercially around the world, 68 are in Canada or under Canadian registration. The fuel quantity gauges in these helicopters are operated by probes located in the centre cell and the right forward fuel cell. If the centre fuel cell does not contain any fuel, the fuel quantity gauge is operated solely by the probes in the right forward cell. The fuel quantity gauge does not directly register fuel in the left forward cell. The left forward fuel cell contains a float-switch used to activate the low-fuel warning light. The fuel quantity indicating system does not directly measure the amount of fuel in the left forward cell. Therefore, unless the fuel level in both forward cells is equal, the gauge will indicate an incorrect amount of fuel remaining. For the same reason, the fuel low-level warning system, which does not directly measure the fuel in the right forward cell, can read incorrectly. Either of these indications could lead pilots to believe that there is more fuel than is actually available and to continue flight operations until fuel exhaustion. When the right boost pump is inoperative, some fuel in the right cell is not available because fuel transfer via the fuel cell interconnects is slower than engine fuel usage. At the same time, the fuel quantity gauge indicates more fuel than is actually on board because the fuel quantity indicator is only getting information from the right fuel cell, which has fuel trapped in it. From the moment the right boost pump becomes inoperative, the quantity of fuel indicated on the gauge would decrease slowly; the system measures the amount of fuel in the right forward fuel cell, and doubles that amount for the fuel quantity indicator. However, the fuel in the right forward cell is being depleted only by the amount of fuel that flows through the interconnect line to the left cell. The actual amount of usable fuel remaining would be difficult for the pilot to determine in flight. The low-fuel light, which gets its information from the left fuel cell, will illuminate as the fuel level in the left cell decreases below a set level. This information could easily be misinterpreted by pilots. The actual flying time remaining before fuel starvation following a loss of a right boost pump would be somewhat more than half of what it would be with both boost pumps operating. The flight manuals for the Bell 214B or the Bell 205 do not explain these symptoms. There are notes that the unusable fuel is 103 pounds in the event of a boost pump failure on the 214B and 59 pounds unusable in the same situation in the Bell 205. The manuals do not contain information explaining that the fuel quantity indicating system may provide incorrect information. Boost pump failures are common in Bell 214B and Bell 205 helicopters. The boost pumps have no time limit before overhaul and are normally kept in service until they fail. The consequences of fuel starvation in flight are serious. There is insufficient information readily available to pilots operating Bell 214B and Bell 205 helicopters to reasonably expect that they would take appropriate action in the event of a boost pump malfunction or a loss of fuel pressure for any other reason. Therefore, the Board recommends, for the consideration of Bell Helicopter Textron and the Minister of Transport, that: